import math
x1,y1,x2,y2=map(float, input().split())
a = (x1-x2)**2
b = (y1-y2)**2
print(math.sqrt(a+b)) import math math x1,y1,x2,y2=map(float, input().split()) x1 map(float, input().split()) map float input().split() ().split () input split y1 x2 y2 a = (x1-x2)**2 a (x1-x2)**2 x1-x2 x1 x2 2 b = (y1-y2)**2 b (y1-y2)**2 y1-y2 y1 y2 2 print(math.sqrt(a+b)) print math.sqrt(a+b) math.sqrt math sqrt a+b a b y1,x2,y2=map(float, input().split()) map(float, input().split()) y1 b = (y1-y2)**2 (y1-y2)**2 b x1,y1,x2,y2=map(float, input().split()) map(float, input().split()) x1 x2,y2=map(float, input().split()) map(float, input().split()) x2 y2=map(float, input().split()) map(float, input().split()) y2 a = (x1-x2)**2 (x1-x2)**2 a
import math
x1,y1,x2,y2=map(float, input().split())
a = (x1-x2)**2
b = (y1-y2)**2
print(math.sqrt(a+b))
